Gas Hydrates Phase Equilibria
and Formation from High Concentration NaCl Brines
up to 200 MPa

Gas
hydrate phase equilibrium and kinetics at high NaCl concentrations
(near and at saturation in solution) and very high pressures (up to
∼200 MPa) are investigated to study the interplay of hydrate
formation and salt precipitation. Limited experimental data above
80 MPa exist for hydrate phase equilibrium in high salinity systems.
This study reveals the unusual formation of gas hydrates under these
extreme conditions of high salinity and very high pressure. In particular,
the results demonstrate that hydrates can form from saturated salt
solutions, and the formation of hydrates and salt precipitation are
competing effects. It is determined that hydrates will remain in equilibrium
with a saturated salt solution, with the amount of salt precipitation
determined by the amount of hydrates formed. These data are essential
fundamental data for gas hydrates applications in the oil and gas
production flow assurance and seawater desalination.